A stress-enhanced model for discovery of disease-modifying gene: Ece1-suppresses the toxicity of α-synuclein A30P
A stress-enhanced model for discovery of disease-modifying gene: Ece1-suppresses the toxicity of α-synuclein A30P
复制标题
DOI：
10.1016/j.nbd.2018.03.003
复制
发表时间：
2018-06-01
影响因子：
6.1
通讯作者：
Tully，Tim
中科院分区：
文献类型：
--
作者：
Chen，Alex Yen-Yu;Tully，Tim
帕金森病（PD）是一种进行性运动神经退行性疾病，其特征是黑质多巴胺能神经元的选择性丢失。疾病病因的复杂性包括遗传和环境因素。目前还没有有效的药物可以改变疾病进展并保护多巴胺神经元免于变性。人α-突触核蛋白A30 P（A30 P）是一种在早发性PD中发现的突变基因，在转A30 P基因的果蝇和小鼠中表现出选择性的多巴胺神经元丢失。百草枯（PQ）是一种除草剂和氧化应激发生器，与散发性PD有关。我们假设重要的PD修饰基因在物种间是保守的，并且在表达PD相关基因（如A30 P）的动物中对氧化应激表现出独特的转录变化。我们还假设，PD修饰基因的操作将提供跨物种的神经保护。为了识别疾病修饰基因，我们进行了两个独立重复的微阵列实验，捕获A30 P果蝇的全基因组转录变化，长期喂食PQ污染的食物。我们假设，鉴定疾病修饰基因的最佳时间点是在疾病早期阶段，当苍蝇显示出A30 P转基因和PQ治疗的最大联合毒性时，并且有效的疾病修饰基因是在A30 P表达中而不是在野生型动物中显示出对氧化应激的转录变化的那些。果蝇脑啡肽酶3（Neprilysin 3，Nep 3）是一个高度保守的基因。它的小鼠和人类同源物是内皮素转换酶-1（Ece 1）。为了研究Ece 1的神经保护作用，我们使用NS 1细胞和表达A30 P的小鼠中脑神经元，用或不用PQ处理。我们发现，ECE 1表达保护A30 P对细胞活力的毒性，对轴突生长和改善A30 P的积累在体外。ECE 1在体内的表达抑制了多巴胺神经元的丢失，并减轻了A30 P表达小鼠相应的运动障碍。我们的研究利用了一种新的方法，使用压力增强的PD动物模型来识别疾病修饰基因。
Parkinson's disease (PD) is a progressive motor neurodegenerative disorder, characterized by a selective loss of dopaminergic neurons in the substantia nigra. The complexity of disease etiology includes both genetic and environmental factors. No effective drug that can modify disease progression and protect dopamine neurons from degeneration is presently available. Human α-Synuclein A30P (A30P) is a mutant gene identified in early onset PD and showed to result selective dopamine neuron loss in transgenic A30P flies and mice. Paraquat (PQ) is an herbicide and an oxidative stress generator, linked to sporadic PD. We hypothesized that vital PD modifier genes are conserved across species and would show unique transcriptional changes to oxidative stress in animals expressing a PD-associated gene, such as A30P. We also hypothesized that manipulation of PD modifier genes would provide neuroprotection across species. To identify disease modifier genes, we performed two independently-duplicated experiments of microarray, capturing genome-wide transcriptional changes in A30P flies, chronically fed with PQ-contaminated food. We hypothesized that the best time point of identifying a disease modifier gene is at time when flies showed maximal combined toxicity of A30P transgene and PQ treatment during an early stage of disease and that effective disease modifiers gene are those showing transcriptional changes to oxidative stress in A30P expressing and not in wild type animals. Fly Neprilysin3 (Nep3) is one identified gene that is highly conserved. Its mouse and human homolog is endothelin-converting enzyme-1 (Ece1). To investigate the neuroprotective effect of Ece1, we used NS1 cells and mouse midbrain neurons expressing A30P, treated with or without PQ. We found that ECE1 expression protected against A30P toxicity on cell viability, on neurite outgrowth and ameliorated A30P accumulationin vitro. Expression of ECE1in vivosuppressed dopamine neuron loss and alleviated the corresponding motor deficits in mice with A30P-expression. Our study leverages a new approach to identify disease modifier genes using a stress-enhanced PD animal model.